The Stuxnet worm is mutating and wreaking further havoc on computerised industrial equipment in Iran where about 30,000 IP addresses have already been infected, IRNA news agency reported on Monday.

"The attack is still ongoing and new versions of this virus are spreading," Hamid Alipour, deputy head of Iran's Information Technology Company, was quoted as saying by IRNA, Iran's official news agency.

Stuxnet, which was publicly identified in June, was tailored for Siemens supervisory control and data acquisition, or SCADA, systems commonly used to manage water supplies, oil rigs, power plants and other industrial facilities.

The self-replicating malware has been found lurking on Siemens systems mostly in India, Indonesia and Pakistan, but the heaviest infiltration appears to be in Iran, according to researchers.

The hackers, who enjoyed "huge investments" from a series of foreign countries or organisations, designed the worm to exploit five different security vulnerabilities, Alipour said while insisting that Stuxnet was not a "normal" worm.

He said his company had begun the cleanup process at Iran's "sensitive centres and organisations," the report said.

Analysts say Stuxnet may have been designed to target Iran's nuclear facilities. But Iranian officials have denied the Islamic republic's first nuclear plant at Bushehr was among the addresses penetrated by the worm.

"This virus has not caused any damage to the main systems of the Bushehr power plant," Bushehr project manager Mahmoud Jafari said on Sunday.

He, however, added the worm had infected some "personal computers of the plant's personnel."

Alipour, whose company is tasked with planning and developing networks in Iran, said personal computers were also being targeted by the malware.

"Although the main objective of the Stuxnet virus is to destroy industrial systems, its threat to home computer users is serious," Alipour said.

The worm is able to recognise a specific facility's control network and then destroy it, according to German computer security researcher Ralph Langner, who has been analysing the malicious software.

Langner said he suspected Stuxnet was targeting Bushehr nuclear power plant, where unspecified problems have been blamed for delays in getting the facility fully operational.

Iran's nuclear ambitions are at the heart of a conflict between Tehran and the West, which suspects the Islamic republic is seeking to develop atomic weapons under the cover of a civilian drive.

Tehran denies the allegation and has pressed on with its enrichment programme -- the most controversial aspect of its nuclear activities -- despite four sets of UN Security Council sanctions.

earlier related report
Thyssen freezes business in Iran
Berlin (UPI) Sep 27, 2010 - Germany's biggest industrial conglomerate, ThyssenKrupp, said it will freeze all new business with Iran.

It said the decision would take effect immediately and that the company would scrap existing contracts with the Islamic Republic in response to stiff sanctions slapped against Tehran.

"By halting business with Iran we are supporting the sanctions policies of the Federal Republic of Germany, the European Union and the United States," ThyssenKrupp Chief Executive Officer Ekkehard Schulz said in a statement.

ThyssenKrupp is the latest German business group to protest Iran's nuclear policy. Its decision came shortly after foreign ministers of the world's major powers told Iran they hoped for an early negotiated solution to the standoff over its nuclear program.

Western powers have insisted that Tehran return to the negotiating table over its controversial nuclear program, which it insists is intended for peaceful purposes only.

Luxury carmaker Daimler had previously announced plans to sell its 30 percent stake in an Iranian engine manufacturer and to freeze its planned export of cars and trucks to Iran.

In July, BP stopped supplying jet fuel to Iran Air at Germany's Hamburg Airport as Lloyds said it wouldn't insure or reinsure petroleum shipments into Iran.

A ThyssenKrupp spokesman commenting on the company's decision said Iran accounted for less than 0.5 percent of group revenues of $54.42 billion in its fiscal year. Most of the group's existing operations in Iran concerns engineering projects.

"The latest executive board decision prohibits all new business with Iran and thus goes beyond the current sanctions measures, which relate primarily to the petroleum sector (oil and gas)," ThyssenKrupp said in a statement.

For many years, ThyssenKrupp was part-owned by Iran, a business relationship stemming from the shah's regime in 1970s. Until then, the company bought enough of its remaining shares in 2003 to avoid being put on a U.S. government blacklist.

Despite the suspension by a string of German business, trade with Iran hasn't been affected overall, analysts and interest groups argue. A show of new statistics revealed that Germany exported 14 percent more goods to Iran in the first half of 2010 compared to the previous year, with July figures at a similarly high level.

"Bureaucratic delays cannot be allowed to block the urgent implementation of sanctions," Deidre Berger, director of the American Jewish Committee's Berlin office, said in a release. "We also urge the German government to respond favorably to the American request to shut down the Hamburg headquarters of the European-Iranian trade bank, which has played a major role in assisting Iran's nuclear ambitions."